aboutsummaryrefslogtreecommitdiff
path: root/gdb/arm-netbsd-tdep.c
blob: aa4d15df4c62582edec2a456fe61f8a7317c23f4 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
/* Target-dependent code for NetBSD/arm.

   Copyright (C) 2002-2022 Free Software Foundation, Inc.

   This file is part of GDB.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

#include "defs.h"
#include "osabi.h"

#include "arch/arm.h"
#include "arm-netbsd-tdep.h"
#include "netbsd-tdep.h"
#include "arm-tdep.h"
#include "regset.h"
#include "solib-svr4.h"

/* Description of the longjmp buffer.  */
#define ARM_NBSD_JB_PC 24
#define ARM_NBSD_JB_ELEMENT_SIZE ARM_INT_REGISTER_SIZE

/* For compatibility with previous implementations of GDB on arm/NetBSD,
   override the default little-endian breakpoint.  */
static const gdb_byte arm_nbsd_arm_le_breakpoint[] = {0x11, 0x00, 0x00, 0xe6};
static const gdb_byte arm_nbsd_arm_be_breakpoint[] = {0xe6, 0x00, 0x00, 0x11};
static const gdb_byte arm_nbsd_thumb_le_breakpoint[] = {0xfe, 0xde};
static const gdb_byte arm_nbsd_thumb_be_breakpoint[] = {0xde, 0xfe};

/* This matches struct reg from NetBSD's sys/arch/arm/include/reg.h:
   https://github.com/NetBSD/src/blob/7c13e6e6773bb171f4ed3ed53013e9d24b3c1eac/sys/arch/arm/include/reg.h#L39
 */
struct arm_nbsd_reg
{
  uint32_t reg[13];
  uint32_t sp;
  uint32_t lr;
  uint32_t pc;
  uint32_t cpsr;
};

void
arm_nbsd_supply_gregset (const struct regset *regset, struct regcache *regcache,
			 int regnum, const void *gregs, size_t len)
{
  const arm_nbsd_reg *gregset = static_cast<const arm_nbsd_reg *>(gregs);
  gdb_assert (len >= sizeof (arm_nbsd_reg));

  /* Integer registers.  */
  for (int i = ARM_A1_REGNUM; i < ARM_SP_REGNUM; i++)
    if (regnum == -1 || regnum == i)
      regcache->raw_supply (i, (char *) &gregset->reg[i]);

  if (regnum == -1 || regnum == ARM_SP_REGNUM)
    regcache->raw_supply (ARM_SP_REGNUM, (char *) &gregset->sp);

  if (regnum == -1 || regnum == ARM_LR_REGNUM)
    regcache->raw_supply (ARM_LR_REGNUM, (char *) &gregset->lr);

  if (regnum == -1 || regnum == ARM_PC_REGNUM)
    {
      CORE_ADDR r_pc = gdbarch_addr_bits_remove (regcache->arch (), gregset->pc);
      regcache->raw_supply (ARM_PC_REGNUM, (char *) &r_pc);
    }

  if (regnum == -1 || regnum == ARM_PS_REGNUM)
    {
      if (arm_apcs_32)
	regcache->raw_supply (ARM_PS_REGNUM, (char *) &gregset->cpsr);
      else
	regcache->raw_supply (ARM_PS_REGNUM, (char *) &gregset->pc);
    }
}

static const struct regset arm_nbsd_regset = {
  nullptr,
  arm_nbsd_supply_gregset,
  /* We don't need a collect function because we only use this reading registers
     (via iterate_over_regset_sections and fetch_regs/fetch_register).  */
  nullptr,
  0
};

static void
arm_nbsd_iterate_over_regset_sections (struct gdbarch *gdbarch,
				       iterate_over_regset_sections_cb *cb,
				       void *cb_data,
				       const struct regcache *regcache)
{
  cb (".reg", sizeof (arm_nbsd_reg), sizeof (arm_nbsd_reg), &arm_nbsd_regset,
      NULL, cb_data);
  /* cbiesinger/2020-02-12 -- as far as I can tell, ARM/NetBSD does
     not write any floating point registers into the core file (tested
     with NetBSD 9.1_RC1).  When it does, this function will need to read them,
     and the arm-netbsd gdbarch will need a core_read_description function
     to return the right description for them.  */
}

static void
arm_netbsd_init_abi_common (struct gdbarch_info info,
			    struct gdbarch *gdbarch)
{
  arm_gdbarch_tdep *tdep = gdbarch_tdep<arm_gdbarch_tdep> (gdbarch);

  tdep->lowest_pc = 0x8000;
  switch (info.byte_order)
    {
    case BFD_ENDIAN_LITTLE:
      tdep->arm_breakpoint = arm_nbsd_arm_le_breakpoint;
      tdep->thumb_breakpoint = arm_nbsd_thumb_le_breakpoint;
      tdep->arm_breakpoint_size = sizeof (arm_nbsd_arm_le_breakpoint);
      tdep->thumb_breakpoint_size = sizeof (arm_nbsd_thumb_le_breakpoint);
      break;

    case BFD_ENDIAN_BIG:
      tdep->arm_breakpoint = arm_nbsd_arm_be_breakpoint;
      tdep->thumb_breakpoint = arm_nbsd_thumb_be_breakpoint;
      tdep->arm_breakpoint_size = sizeof (arm_nbsd_arm_be_breakpoint);
      tdep->thumb_breakpoint_size = sizeof (arm_nbsd_thumb_be_breakpoint);
      break;

    default:
      internal_error (__FILE__, __LINE__,
		      _("arm_gdbarch_init: bad byte order for float format"));
    }

  tdep->jb_pc = ARM_NBSD_JB_PC;
  tdep->jb_elt_size = ARM_NBSD_JB_ELEMENT_SIZE;

  set_gdbarch_iterate_over_regset_sections
    (gdbarch, arm_nbsd_iterate_over_regset_sections);
  /* Single stepping.  */
  set_gdbarch_software_single_step (gdbarch, arm_software_single_step);
}

static void
arm_netbsd_elf_init_abi (struct gdbarch_info info,
			 struct gdbarch *gdbarch)
{
  arm_gdbarch_tdep *tdep = gdbarch_tdep<arm_gdbarch_tdep> (gdbarch);

  arm_netbsd_init_abi_common (info, gdbarch);

  nbsd_init_abi (info, gdbarch);

  if (tdep->fp_model == ARM_FLOAT_AUTO)
    tdep->fp_model = ARM_FLOAT_SOFT_VFP;

  /* NetBSD ELF uses SVR4-style shared libraries.  */
  set_solib_svr4_fetch_link_map_offsets
    (gdbarch, svr4_ilp32_fetch_link_map_offsets);
}

void _initialize_arm_netbsd_tdep ();
void
_initialize_arm_netbsd_tdep ()
{
  gdbarch_register_osabi (bfd_arch_arm, 0, GDB_OSABI_NETBSD,
			  arm_netbsd_elf_init_abi);
}